JPS6195793A - Laser beam machine - Google Patents

Abstract

PURPOSE:To perform a good machining even against the object to be machined having high reflection factor by stopping the movement by the measured intensity of the reflecting laser beam by the object to be machined in the machine relatively moving the spot of the laser beam irradiated on the object to be machined to the object to be machined. CONSTITUTION:Suppose a machining is performed upto a point PB with starting the machining of the object 5 to be machined from a point PA. When the machining is suspended at this point and a laser beam 2 is made to be reflected on the surface of the object 5 to be machined, the signal A outputted from the detector 17 detecting the intensity of the reflecting beam 16 thereof is increased. It is inputted into a comparator 21 and compared with the reference signal F showing the allowable intensity of the reflecting beam 16 emitted from a setter 20 hereupon and the signal G of A>=F is inputted into a NC unit 8 and the movement of a XY stage 6 or the object 5 to be machined is stopped. The object 5 to be machined is then subjected to drilling, the intensity of the reflecting beam 16 is gradually reduced, the output of the comparator 21 is reversed and the movement of the object 5 to be machined is started.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laser processing device, and particularly to a laser processing device suitable for processing difficult-to-cut materials that reflect laser light.

[Conventional technology]

As a conventional laser processing apparatus, there is one shown in FIG. 6, for example. In this figure, a laser beam (2) emitted from a laser oscillator (11) is guided by a pend mirror (3) to a workpiece (5) via a condenser lens system (4). The workpiece (5) is placed on an XY table (6), and this XY table r6
) are two-dimensionally moved by drive motors (7a) and (7b). This XY table (
6), the workpiece (5) is cut into an arbitrary shape. The data regarding this processed shape is obtained from the NC device (8).
The NC device (8) is stored in the drive motor (7).
a) and (7b), respectively.

Next, the operation of the above conventional example will be explained. First, a laser beam (2) is output from a laser oscillator (1),
The optical path is bent by the pend mirror (3) and enters the workpiece (5). At this time, the condenser lens system (4)
Therefore, the laser beam (2) is 106 to 108 W/i
The light is focused into a high energy density spot and irradiated onto the workpiece (5).

On the other hand, the workpiece (5) is driven by a drive motor (7a) based on the machining shape data stored in the NC device (8).

(7b) is driven to move the XY table (6), thereby moving in accordance with the machining shape data.

As a result, the spot of the laser beam (2) moves relatively over the workpiece (5) along the processed shape, and a predetermined process is performed.

As mentioned above, laser processing equipment has the feature of being able to perform various types of processing with high efficiency by using the high energy density of a focused laser beam to evaporate and melt away the workpiece. There is.

[Problem that the invention seeks to solve]

However, in such a laser processing apparatus, a workpiece having a high beam reflectance, such as aluminum (At), #
When processing I (Cu), silver (Au), etc., there is a problem that most of the laser beam is reflected by the surface, and there are cases where the processing cannot be carried out satisfactorily. During processing, once the processing of the workpiece is interrupted, the reflected light of the laser beam increases, and the power of the laser beam that contributes to processing decreases, resulting in the inconvenience that processing continues.

The present invention has been made in view of these points, and an object of the present invention is to provide a laser processing device that can satisfactorily process even workpieces with high beam reflectance. .

[Means for solving problems]

The laser processing apparatus according to the present invention includes a means for detecting the intensity of the laser beam reflected by the workpiece, and a means for detecting the relative strength of the workpiece and the spot of the laser beam when the intensity of the detected laser beam is above a certain level. The invention is characterized in that it includes means for stopping the target movement.

[Effect]

According to the present invention, it is detected whether or not the machining operation has been interrupted based on the intensity of the laser beam reflected by the workpiece. Then, when it is determined that the machining operation is interrupted, the relative movement of the workpiece with respect to the laser beam is stopped, and when the machining operation using the laser beam is started, the relative movement is started again, and the machining operation is started again. continues.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A laser processing apparatus according to the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

FIG. 1 shows an embodiment of a laser processing apparatus according to the present invention. In this Figure 1, the laser oscillator (
In the optical path between 1) and the pend mirror (3), there is a beam splitter Q! 9 is provided. A part of the laser beam (2) output from this beam splitter (laser oscillator +1 by 1!9) is reflected upward in the figure and is detected by detector a1 as a monitor laser beam α barrel. . The detection signal output from this detector σ9 is shown as a laser beam (corresponding to the intensity of l, signal 03). Also, a part of the laser beam (2) reflected from the workpiece (5) side by the beam splitter (one) is reflected downward in the figure, and this reflected light
71. The detection signal output from this detector surface corresponds to the intensity of the reflected light flE9,
Shown as signal (5).

Next, as shown in FIG. 2, the signal output from the detector ση is input to the comparator Qυ.

A setter 1 is connected to the other input end of the comparator Qρ, and a reference signal ■ is input to the comparator Qυ. The output end of the comparator Q is connected to the NC device (ft f8), so that the control signal (2) is input to the NC device (8).

Next, the overall operation of the above embodiment will be explained. First, it is assumed that machining of the workpiece (5) is started from point (PA) and machined to point (PB) in the same way as in the conventional method. This point (
If the processing is interrupted at point PB) and the laser beam (2) is reflected by the surface of the workpiece (5), the signal (t) output from the detector qη will be as shown in Figure 6. This will increase as shown in (2). This signal is input to the comparator Qη, and on the other hand, the signal 2, which serves as the level reference shown in FIG. 3 (C), is input from the setting device (4) to the comparator (C). This signal is the workpiece (
5) indicates the allowable intensity of the reflected light αQ of the laser beam (2), and the intensity of the reflected light tte, that is, the signal (
When the signal [F] becomes larger than the signal [F], this becomes the comparator (c).
The output 0 is as shown in FIG. 6 (■). The rising timing of the signal C) is indicated by (to), and the signal Q is inverted from the logical value "0" to "1".

When this signal 0 is input to the NC device (8), the driving of the drive motors (7a) and (7b) is stopped, and the movement of the XY table (6) and thus the workpiece (5) is stopped.

Therefore, the intensity of the reflected light tte of the laser beam (2) at each point (2) on the workpiece (5) gradually decreases.

Comparator for this? The output of 9 is the logical value “1” to “
0”, and this is the NC device! ffi
(It is input to 8+, and the movement of the XY table (6) and thus the workpiece (5) is started. As a result, cutting of the uncuttable part α1 is performed consecutively to the cuttable part (9). It will be.

Next, another embodiment of the present invention will be described with reference to FIG.

This embodiment is designed to cope well with changes in the intensity of the laser beam (2) output from the laser oscillator (1). In this embodiment, as shown in FIG.
3) are each input to the divider -, C=A/B
・The calculation is now performed. The result of this division, 0, is then input to the comparator Q). The rest is the same as the embodiment described above. Next, to explain the overall operation of this embodiment, it is assumed that the intensity of the reflected light σe changes as the laser output of the laser oscillator (1) changes. In this case, detector i
As the output of ll changes, the output of the detector αη (g) also changes correspondingly, and the result of division is C).
does not change. On the other hand, when the processing is interrupted and the intensity of the reflected light fle increases, the laser output of the laser oscillator (1) does not change, so only the output (4) of the detector Uη increases. Therefore, even if the intensity of the laser beam (2) changes, the sensitivity to the detection of the intensity change of the reflected light (l[9) can be kept constant.

Next, still another embodiment of the present invention will be described with reference to FIG.

This embodiment, like the embodiment shown in FIG. 4 described above, aims to equalize the sensitivity, but focuses on the fact that the laser output of the laser oscillator fil increases when there is reflected light.

In FIG. 5, a setting signal 0 of the laser output setting device (g) of the laser oscillator (1) is input to the laser oscillator (1) and also to the divider (c). On the other hand,
The signal of the detector σ9) is also input to this divider (c), and the calculation E=B/D is executed by the divider -, and the result ■ is input to the comparator Q+). ing.

To explain the operation of this embodiment, first, when the intensity of the output laser beam (2) of the laser oscillator (1) changes due to a change in the setting signal 0 of the laser output setting device (b),
The output signal (B) of detector four will also change accordingly. Therefore, the result of division (■) does not change. On the other hand, when the processing is interrupted and the reflected beam from the workpiece (5) increases, this beam enters the laser oscillator (1) and the laser output of the laser oscillator (1) increases.

For this reason, although the signal ■ of the laser output setting device (c) does not change, the signal of the detector (signal field output from 1'l) increases, and the output signal [F] of the divider - also increases. That will happen. Therefore, the detection sensitivity can be kept constant in the same manner as in the embodiments described above.

As explained above, reflected light from the workpiece increases,
If the machining operation is continued after the machining has been interrupted, the interrupted machining state will not be recovered and the machining will be incomplete. Therefore, in such a situation, the processing capacity is automatically restored by stopping the movement of the workpiece using the NC device and restarting the movement of the workpiece after the processing capacity is restored. I can do it.

In addition, although the case of the cutting process was shown in the said Example, this invention is not limited to this at all, and may be performed by other types of process. Further, the design of the circuit is also arbitrary, and a microprocessor or the like may be used.

〔Effect of the invention〕

As explained above, according to the laser processing apparatus according to the present invention, when the intensity of the reflected light from the workpiece exceeds a preset value, the movement of the workpiece with respect to the laser beam is stopped. Therefore, the processing ability is automatically restored, and even difficult-to-process materials such as aluminum and copper that reflect laser light can be processed satisfactorily.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing one embodiment of the laser processing device according to the present invention, Fig. 2 is a block diagram showing a circuit connected to the device shown in Fig. 1, and Fig. A time chart, FIG. 4 is a block diagram showing another embodiment of the present invention,
FIG. 5 is a block diagram showing still another embodiment of the present invention, and FIG. 6 is an explanatory diagram showing an example of a conventional laser processing apparatus. In the figure, (1) is a laser oscillator, (2) is a laser beam, (5) is a workpiece, (6) is an XY stage, (8) is a
) is the NC device, Q7), Ql is the detector, σe is the reflected light,
@ is a setter, Q9 is a comparator, and (c) is a divider. Note that the same reference numerals in each figure indicate the same or corresponding parts. Figures 5 and 6 of the agent, Patent Attorney Mitsuru Kimura

Claims (2)

[Claims] (1) In a laser processing device that performs desired processing by moving a spot of a laser beam irradiated onto a workpiece relative to the workpiece, the laser beam reflected by the workpiece is The method includes a detection means for detecting the intensity, and a means for stopping the relative movement of the laser beam spot and the workpiece when the intensity of the reflected light is detected by the means to be above a certain level. Laser processing equipment featuring: (2) The laser processing apparatus according to claim 1, wherein the detection means detects the intensity of the reflected light as a ratio of the intensity of the laser light irradiated onto the workpiece.